mgw: Allow auditing speciall 'null' endpoint
This is a special endpoint which can always be audited. This is useful
for clients who wish to submit requests to osmo-mgw periodically to find
out whether the MGW is still reachable. This endpoint will be used by
libomso-mgcp-client as default target endpoint to implement such
feature.
This "null" Endpoint is osmo-mgw specific, not described in MGCP specs.
Related: SYS#6481
Change-Id: Ia409b16e9211e6261e2e0f21288544289d6f3733
diff --git a/doc/manuals/chapters/mgcp_endpoints.adoc b/doc/manuals/chapters/mgcp_endpoints.adoc
index 797fdea..2fb6e16 100644
--- a/doc/manuals/chapters/mgcp_endpoints.adoc
+++ b/doc/manuals/chapters/mgcp_endpoints.adoc
@@ -91,4 +91,10 @@
not yet useable.
NOTE: the VTY command "show mgcp" can be used to get a list of all available
-endpoints (including identifiers)
\ No newline at end of file
+endpoints (including identifiers)
+
+=== The `null` endpoint
+
+OsmoMGW offers a special `null@<domain>` endpoint which can be audited at all times.
+This is useful for MGCP clients who wish to submit requests to OsmoMGW
+periodically to find out whether it is still reachable and in a working state.
\ No newline at end of file
diff --git a/include/osmocom/mgcp/mgcp_endp.h b/include/osmocom/mgcp/mgcp_endp.h
index 08b966f..7bf034b 100644
--- a/include/osmocom/mgcp/mgcp_endp.h
+++ b/include/osmocom/mgcp/mgcp_endp.h
@@ -133,6 +133,7 @@
int mgcp_endp_claim(struct mgcp_endpoint *endp, const char *callid);
void mgcp_endp_update(struct mgcp_endpoint *endp);
bool mgcp_endp_is_wildcarded(const char *epname);
+bool mgcp_endp_is_null(const char *epname);
struct mgcp_endpoint *mgcp_endp_by_name_trunk(int *cause, const char *epname,
const struct mgcp_trunk *trunk);
struct mgcp_endpoint *mgcp_endp_by_name(int *cause, const char *epname,
diff --git a/src/libosmo-mgcp/mgcp_endp.c b/src/libosmo-mgcp/mgcp_endp.c
index 2bf15e0..20088b7 100644
--- a/src/libosmo-mgcp/mgcp_endp.c
+++ b/src/libosmo-mgcp/mgcp_endp.c
@@ -229,6 +229,17 @@
return false;
}
+/*! Check if the given epname refers to a "null" endpoint.
+ * \param[in] epname endpoint name to check
+ * \returns true if epname refers to "null"" endpoint, else false. */
+bool mgcp_endp_is_null(const char *epname)
+{
+ if (strncasecmp(epname, "null@", 5) == 0)
+ return true;
+
+ return false;
+}
+
/*! Find an endpoint by its name on a specified trunk.
* \param[out] cause pointer to store cause code, can be NULL.
* \param[in] epname endpoint name to lookup.
diff --git a/src/libosmo-mgcp/mgcp_protocol.c b/src/libosmo-mgcp/mgcp_protocol.c
index 1fa345b..80e0f8a 100644
--- a/src/libosmo-mgcp/mgcp_protocol.c
+++ b/src/libosmo-mgcp/mgcp_protocol.c
@@ -86,6 +86,9 @@
/* set to true when the request has been classified as wildcarded */
bool wildcarded;
+ /* Set to true when the request is targeted at the "null" endpoint */
+ bool null_endp;
+
/* contains cause code in case of problems during endp/trunk resolution */
int mgcp_cause;
};
@@ -390,7 +393,10 @@
/* Locate endpoint and trunk, if no endpoint can be located try at least to identify the trunk. */
rq.pdata = &pdata;
rq.wildcarded = mgcp_endp_is_wildcarded(pdata.epname);
- rq.endp = mgcp_endp_by_name(&rc, pdata.epname, pdata.cfg);
+ if (!rq.wildcarded)
+ rq.null_endp = mgcp_endp_is_null(pdata.epname);
+ if (!rq.null_endp)
+ rq.endp = mgcp_endp_by_name(&rc, pdata.epname, pdata.cfg);
rq.mgcp_cause = rc;
if (!rq.endp) {
rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_GENERAL_RX_FAIL_NO_ENDPOINT));
@@ -407,14 +413,14 @@
rq.name, pdata.epname);
return create_err_response(cfg, NULL, -rq.mgcp_cause, rq.name, pdata.trans);
}
- } else {
+ } else if (!rq.null_endp) {
/* If the endpoint name suggests that the request refers to a specific endpoint, then the
* request cannot be handled and we must stop early. */
LOGP(DLMGCP, LOGL_NOTICE,
"%s: cannot find endpoint \"%s\", cause=%d -- abort\n", rq.name,
pdata.epname, -rq.mgcp_cause);
return create_err_response(cfg, NULL, -rq.mgcp_cause, rq.name, pdata.trans);
- }
+ } /* else: Handle special "null" endpoint below (with rq.endp=NULL, rq.trunk=NULL) */
} else {
osmo_strlcpy(debug_last_endpoint_name, rq.endp->name, sizeof(debug_last_endpoint_name));
rq.trunk = rq.endp->trunk;
@@ -460,6 +466,11 @@
static struct msgb *handle_audit_endpoint(struct mgcp_request_data *rq)
{
LOGPENDP(rq->endp, DLMGCP, LOGL_NOTICE, "AUEP: auditing endpoint ...\n");
+
+ /* Auditing "null" endpoint is allowed for keepalive purposes. There's no rq->endp nor rq->trunk in this case. */
+ if (rq->null_endp)
+ return create_ok_response(rq->pdata->cfg, NULL, 200, "AUEP", rq->pdata->trans);
+
if (!rq->endp || !mgcp_endp_avail(rq->endp)) {
LOGPENDP(rq->endp, DLMGCP, LOGL_ERROR, "AUEP: selected endpoint not available!\n");
return create_err_response(rq->trunk, NULL, 501, "AUEP", rq->pdata->trans);
@@ -855,7 +866,7 @@
struct mgcp_parse_data *pdata = rq->pdata;
struct mgcp_trunk *trunk = rq->trunk;
struct mgcp_endpoint *endp = rq->endp;
- struct rate_ctr_group *rate_ctrs = trunk->ratectr.mgcp_crcx_ctr_group;
+ struct rate_ctr_group *rate_ctrs;
int error_code = 400;
const char *local_options = NULL;
const char *callid = NULL;
@@ -869,6 +880,14 @@
LOGPENDP(endp, DLMGCP, LOGL_NOTICE, "CRCX: creating new connection ...\n");
+ if (rq->null_endp) {
+ /* trunk not available so rate_ctr aren't available either. */
+ LOGP(DLMGCP, LOGL_ERROR, "CRCX: Not allowed in 'null' endpoint!\n");
+ return create_err_response(pdata->cfg, NULL, 502, "CRCX", pdata->trans);
+ }
+
+ rate_ctrs = trunk->ratectr.mgcp_crcx_ctr_group;
+
/* we must have a free ep */
if (!endp) {
rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_AVAIL));
@@ -1134,7 +1153,7 @@
struct mgcp_parse_data *pdata = rq->pdata;
struct mgcp_trunk *trunk = rq->trunk;
struct mgcp_endpoint *endp = rq->endp;
- struct rate_ctr_group *rate_ctrs = trunk->ratectr.mgcp_mdcx_ctr_group;
+ struct rate_ctr_group *rate_ctrs;
char new_local_addr[INET6_ADDRSTRLEN];
int error_code = 500;
int silent = 0;
@@ -1149,6 +1168,14 @@
LOGPENDP(endp, DLMGCP, LOGL_NOTICE, "MDCX: modifying existing connection ...\n");
+ if (rq->null_endp) {
+ /* trunk not available so rate_ctr aren't available either. */
+ LOGP(DLMGCP, LOGL_ERROR, "MDCX: Not allowed in 'null' endpoint!\n");
+ return create_err_response(pdata->cfg, NULL, 502, "MDCX", pdata->trans);
+ }
+
+ rate_ctrs = trunk->ratectr.mgcp_mdcx_ctr_group;
+
/* Prohibit wildcarded requests */
if (rq->wildcarded) {
LOGPENDP(endp, DLMGCP, LOGL_ERROR,
@@ -1360,7 +1387,7 @@
struct mgcp_parse_data *pdata = rq->pdata;
struct mgcp_trunk *trunk = rq->trunk;
struct mgcp_endpoint *endp = rq->endp;
- struct rate_ctr_group *rate_ctrs = trunk->ratectr.mgcp_dlcx_ctr_group;
+ struct rate_ctr_group *rate_ctrs;
int error_code = 400;
int silent = 0;
char *line;
@@ -1370,10 +1397,18 @@
unsigned int i;
/* NOTE: In this handler we can not take it for granted that the endp
- * pointer will be populated, however a trunk is always guaranteed. */
+ * pointer will be populated, however a trunk is always guaranteed (except for 'null' endp).
+ */
LOGPEPTR(endp, trunk, DLMGCP, LOGL_NOTICE, "DLCX: deleting connection(s) ...\n");
+ if (rq->null_endp) {
+ /* trunk not available so rate_ctr aren't available either. */
+ LOGP(DLMGCP, LOGL_ERROR, "DLCX: Not allowed in 'null' endpoint!\n");
+ return create_err_response(pdata->cfg, NULL, 502, "DLCX", pdata->trans);
+ }
+
+ rate_ctrs = trunk->ratectr.mgcp_dlcx_ctr_group;
if (endp && !mgcp_endp_avail(endp)) {
rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_DLCX_FAIL_AVAIL));
LOGPENDP(endp, DLMGCP, LOGL_ERROR,
@@ -1524,6 +1559,12 @@
LOGP(DLMGCP, LOGL_NOTICE, "RSIP: resetting all endpoints ...\n");
+ if (rq->null_endp) {
+ /* trunk not available so rate_ctr aren't available either. */
+ LOGP(DLMGCP, LOGL_ERROR, "RSIP: Not allowed in 'null' endpoint!\n");
+ return create_err_response(rq->pdata->cfg, NULL, 502, "RSIP", rq->pdata->trans);
+ }
+
if (rq->pdata->cfg->reset_cb)
rq->pdata->cfg->reset_cb(rq->endp->trunk);
return NULL;
@@ -1549,6 +1590,12 @@
LOGP(DLMGCP, LOGL_NOTICE, "RQNT: processing request for notification ...\n");
+ if (rq->null_endp) {
+ /* trunk not available so rate_ctr aren't available either. */
+ LOGP(DLMGCP, LOGL_ERROR, "RQNT: Not allowed in 'null' endpoint!\n");
+ return create_err_response(rq->pdata->cfg, NULL, 502, "RQNT", rq->pdata->trans);
+ }
+
for_each_line(line, rq->pdata->save) {
switch (toupper(line[0])) {
case 'S':
diff --git a/tests/mgcp/mgcp_test.c b/tests/mgcp/mgcp_test.c
index 2374e91..e37bb57 100644
--- a/tests/mgcp/mgcp_test.c
+++ b/tests/mgcp/mgcp_test.c
@@ -77,6 +77,8 @@
#define AUEP1_RET "500 158663169 FAIL\r\n"
#define AUEP2 "AUEP 18983213 ds/e1-2/1@mgw MGCP 1.0\r\n"
#define AUEP2_RET "500 18983213 FAIL\r\n"
+#define AUEP_NULL "AUEP 18983215 null@mgw MGCP 1.0\r\n"
+#define AUEP_NULL_RET "200 18983215 OK\r\n"
#define EMPTY "\r\n"
#define EMPTY_RET NULL
#define SHORT "CRCX \r\n"
@@ -274,6 +276,12 @@
#define MDCX_TOO_LONG_CI_RET "510 18983224 FAIL\r\n"
+#define MDCX_NULL \
+ "MDCX 9 null@mgw MGCP 1.0\r\n" \
+ "I: %s\n"
+
+#define MDCX_NULL_RET "502 9 FAIL\r\n"
+
#define SHORT2 "CRCX 1"
#define SHORT2_RET "510 000000 FAIL\r\n"
#define SHORT3 "CRCX 1 1@mgw"
@@ -392,6 +400,13 @@
#define DLCX_RET_OSMUX DLCX_RET \
"X-Osmo-CP: EC TI=0, TO=0\r\n"
+#define DLCX_NULL \
+ "DLCX 8 null@mgw MGCP 1.0\r\n" \
+ "I: %s\r\n" \
+ "C: 2\r\n"
+
+#define DLCX_NULL_RET "502 8 FAIL\r\n"
+
#define RQNT \
"RQNT 186908780 1@mgw MGCP 1.0\r\n" \
"X: B244F267488\r\n" \
@@ -405,6 +420,13 @@
#define RQNT1_RET "200 186908780 OK\r\n"
#define RQNT2_RET "200 186908781 OK\r\n"
+#define RQNT_NULL \
+ "RQNT 186908782 null@mgw MGCP 1.0\r\n" \
+ "X: B244F267488\r\n" \
+ "S: D/9\r\n"
+
+#define RQNT_NULL_RET "502 186908782 FAIL\r\n"
+
#define PTYPE_IGNORE 0 /* == default initializer */
#define PTYPE_NONE 128
#define PTYPE_NYI PTYPE_NONE
@@ -545,6 +567,20 @@
"m=audio 16008 RTP/AVP 0\r\n" \
"a=ptime:20\r\n"
+#define CRCX_NULL \
+ "CRCX 2 null@mgw MGCP 1.0\r\n" \
+ "m: recvonly\r\n" \
+ "C: 2\r\n" \
+ "L: p:20\r\n" \
+ "\r\n" \
+ "v=0\r\n" \
+ "c=IN IP4 123.12.12.123\r\n" \
+ "m=audio 5904 RTP/AVP 97\r\n" \
+ "a=rtpmap:97 GSM-EFR/8000\r\n" \
+ "a=ptime:40\r\n"
+
+#define CRCX_NULL_RET "502 2 FAIL\r\n"
+
struct mgcp_test {
const char *name;
const char *req;
@@ -586,6 +622,11 @@
{"CRCX", CRCX_X_OSMO_IGN, CRCX_X_OSMO_IGN_RET, 97},
{"MDCX_TOO_LONG_CI", MDCX_TOO_LONG_CI, MDCX_TOO_LONG_CI_RET},
{"CRCX", CRCX_AMR_WITH_FMTP, CRCX_AMR_WITH_FMTP_RET},
+ {"AUEP_NULL", AUEP_NULL, AUEP_NULL_RET},
+ {"CRCX_NULL", CRCX_NULL, CRCX_NULL_RET},
+ {"MDCX_NULL", MDCX_NULL, MDCX_NULL_RET},
+ {"DLCX_NULL", DLCX_NULL, DLCX_NULL_RET},
+ {"RQNT_NULL", RQNT_NULL, RQNT_NULL_RET},
};
static const struct mgcp_test retransmit[] = {
diff --git a/tests/mgcp/mgcp_test.ok b/tests/mgcp/mgcp_test.ok
index 08df5d4..d76e455 100644
--- a/tests/mgcp/mgcp_test.ok
+++ b/tests/mgcp/mgcp_test.ok
Binary files differ